This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. There are many types of regulatory elements at the transcriptional level. Some types of regulatory elements cause positive enhancement of transcription and other negative regulation or ?silencing.? In Saccaromyces cerevisiae some of the most studied and understood types are silencing near telomeres and silent mating loci. Our lab has identified a novel form of silencing in yeast which involves the transcription of tRNA genes by RNA polymerase III. The transcription of pol III tRNA genes has been shown to cause the inhibition of certain RNA polymerase II genes. Deletion of genes shown to cause alleviation of other types of silencing has shown to have no affect on TGM silencing, however previous studies in our lab has uncovered novel proteins that alleviates this phenomena. However, none of these proteins has been shown to possess any silencing ability or to interact with each other. It is our belief that one of these proteins must be interacting with proteins that directly lead to silencing that the tRNA loci. We have acquired duel affinity versions of these proteins and will do pull downs and then use Mass spectrometry to identify novel protein interactions.